Temperature-Programmed Surface Reaction Study of Adsorption and Reaction of H2S on Ceria

H2S adsorption and reaction on CeO2, TiO2, and gamma-Al2O3 were studied by temperature programmed surface reaction (TPSR). Ceria had the best desulfidation ability. The pretreatment atmosphere affected H2S adsorption and reaction on ceria, and desulfidation efficiency increased in the order of inert atmosphere, reducing atmosphere, oxidizing atmosphere. H2S was first adsorbed on pretreated ceria at room temperature. On increasing the temperature in an Ar (99.99%) atmosphere, part of the H2S desorbed below 673 K, and another part reacted with the surface oxygen on ceria to produce sulfur and water below 473 K, and SO2 between 473 and 673 K, which further reacted with lattice oxygen and was transformed into sulfate above 673 K. The sulfate decomposed into SO2 again at 873 K. To avoid the complex regeneration, it is advisable to carry out desulfidation below 673 K when using ceria as adsorbent.